Cyclopentyl compound and process of making same



vention Patented May 28, 1929..

UNITED STATES PA'rENr orrice.

ROGER ADAMS, OF URBANA, ILLINOIS, ASSIGNOR TO ABBOTT LABORATORIES, OF NORTH CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

GYCLOPENTYL COMPOUND AND PROCESS OF MAKING SAME.

No Drawing.

Application filed. January 27, 1928. Serial No. 250,075.

atoms of carbon in the molecule, are stron ly bactericidal against acid-fast bacteria, such as I). Zap/1c or 1). tuberculosis.

These acids may conveniently be prepared by condensation of a cyclopentyl halide or a cyclopentyl alkyl halide with the proper substituted malonic ester, or byccondensation of an onicga-cyclopentyl alkyl nialonic ester, or a cyclopentyl malonic ester with an alkyl halide, followed by'saponilication and elimination of carbon dioxide. These reactions are indicated by the following series of equations:

COOR

l onnwnmx non UOOR coon

CODE

COOR' COOR oooR" coon coon COOH . alkyl group.

WVithout limiting the invention to any par ticular procedure, the following examples will be illustrative of a general method which may be employed for carrying out the intuted dialkyl'malonate and one molecular equivalent of sodium ethylate, and the mixture is refluxed in absolute alcohol until neutral. The alcohol is distilled off, Water is added, and the cyclopentyl-alkyl malonic ester or the cyclopentylalkyl-alkyl malonic ester, as the case may be, is separated and purified.

The malonic ester derivative'thus obtained is treated with alcoholic potassium or sodium hydroxide solution containing four molecular equivalents of potassium or sodium hydroxide; the mixture is refluxed for one or tWo hours. Upen evaporation of the alcohol, addition of water, then acidification with a mineral acid, the malonic acid separates and is readily purified.

The malonic acid thus produced is heated above its melting point and held at that temperature until no more evolution of carbon dioxide takes place. The resulting. product is then distilled in vacuo.

By thisgeneral procedure, the following acids were prepared:

, Ewample 1.

Alpha Cyclopentyl alpha-alkyl acetic acids.

General formula: C H CH (R) COOH.

Physical constants of acid.

Where R is- CslIn Boiling point, 163 C. at 1 min. (Min Boiling point, 177 0. at 1.4 nnn.

Melting point, 4042 C. CioHn Boiling point, 176 at 1.5 mm.

Melting point, 37 U. 0111123..-. Boiling point, 175 at, 1.2 mm. Melting point, 48 C.

Eurmn pie [1.

Omega Cyclopcntylethylalkyl acids.

General formula:

C H CH CH CH (R) COOH.

acetic Where It is- Boiling points of acid.

at 2 mm. a}. 1 mm. at 2 nun. at 1.5 mm.

The examples given illustrate the general methods of preparation and the properties of some of the compounds obtained. The

vscope of the patentis limited neither to the processes specifically described, nor to the compounds mentioned.- By using'a similar process for example, compounds of the forin which y represents zero or more, R represents an aliphatic hydrocarbon group, and Z represents hydrogen, a metal, or a hydrocarbon group such as an alkyl or an alkylen'e.

. 2. The process of making a compound of the type described in claim 1, which includes introducing an alkyl group'and a group containing a cyclopentyl radial into a inalonic ester, followed by saponification and elimination of one mol of carbon dioxide.

Jan. 24, 1928.

ROGER ADAMS. 

